The objectives of this project are to identify and describe the environmental determinants of cancer, particularly within areas of high cancer risk in the U.S., through the use of analytic epidemiologic techniques. Toward this end, the Branch has initiated a series of case-control studies designed to test a number of hypotheses regarding the origins of cancer. Begun this year and presently ongoing are studies of lung cancer in northeast Florida and Tidewater Virginia; colon cancer in rural Nebraska; liver cancer in southeast Texas; bladder cancer in rural New England; esophageal cancer in Washington, D.C.; and nasal and oral cancer in North Carolina, all areas of exceptionally high risk for these tumors. A case-control study of lung cancer in coastal Georgia was completed during the year. Data from the approximately 13000 interviews revealed a significantly increased risk for this cancer associated with shipyard employment during World War II that was not accounted for by other occupational exposures or by cigarette smoking.